Climate change is one of the greatest threats of our era. The City of Stockholm aims to become a fossil free city by 2040 and citizens want to help: eight in ten residents say they want to be more active in the fight against climate change. Still, the City lacks solutions that engage residents or provide them with a way to directly contribute to the City’s goal.
Stockholm’s Biochar Project aims to reduce carbon emissions by enabling citizens to be part of carbon sequestration. Residents will provide plant waste to the City, which will produce biochar – a charcoal-like product that can sequester carbon in soil for thousands of years. Biochar, when placed in plant beds, improves soil structure, encourages plant growth, and helps to purify storm water run-off. Additionally, a by-product of the biochar production process is pyrolysis gas, which will be used to generate energy for the City’s district heating system. While there are examples of biochar use across Europe, Stockholm will implement the first large-scale collaboration between local authorities and citizens in the generation of the product.
The City’s first physical biochar plant will be operational in 2016. Stockholm anticipates producing 7,000 tons of biochar by 2020, which will sequester 25,200 tons of CO2 (the equivalent of taking 3,500 cars off the road) and produce a corresponding 25,200 megawatt hours of energy.